Linear and pivotal actuators, whether hydraulic, pneumatic, or electric, are used for a multitude of actions involving moving one structure relative to another. These actuators are most often used in pairs due to the size of the structure to be moved, or due to the instability of the structure. However, using a pair of actuators often causes problems due to the inherent difficulty in moving the actuators precisely together. If one actuator moves slightly before the other, or if one actuator moves slightly faster than the other, binding and twisting can occur in the structure being moved.
In the room extending mechanisms for mobile homes and recreational vehicles which are known in the art, the actuators slide a moveable structure, as perhaps a small living area, in a horizontal plane. Binding is a common problem when one actuator leads or lags the other. The standard remedy is to reverse the actuators for a moment in hopes of relieving the binding.